COVID-19 and athletes: Endurance sport and activity resilience study-CAESAR study.

Background: The COVID-19 pandemic and imposed restrictions influenced athletic societies, although current knowledge about mild COVID-19 consequences on cardiopulmonary and physiologic parameters remains inconclusive. This study aimed to assess the impact of mild COVID-19 inflection on cardiopulmonary exercise test (CPET) performance among endurance athletes (EA) with varied fitness level. Materials and Methods: 49 EA (n _male = 43, n _female = 6, mean age = 39.94 ± 7.80 yr, height = 178.45 cm, weight = 76.62 kg; BMI = 24.03 kgm ^-2 ) underwent double treadmill or cycle ergometer CPET and body analysis (BA) pre- and post-mild COVID-19 infection. Mild infection was defined as: (1) without hospitalization and (2) without prolonged health complications lasting for >14 days. Speed, power, heart rate (HR), oxygen uptake (VO ₂ ), pulmonary ventilation, blood lactate concentration (at the anaerobic threshold (AT)), respiratory compensation point (RCP), and maximum exertion were measured before and after COVID-19 infection. Pearson's and Spearman's r correlation coefficients and Student t-test were applied to assess relationship between physiologic or exercise variables and time. Results: The anthropometric measurements did not differ significantly before and after COVID-19. There was a significant reduction in VO ₂ at the AT and RCP (both p < 0.001). Pre-COVID-19 VO ₂ was 34.97 ± 6.43 ml kg·min ^-1 , 43.88 ± 7.31 ml kg·min ^-1 and 47.81 ± 7.81 ml kg·min ^-1 respectively for AT, RCP and maximal and post-COVID-19 VO ₂ was 32.35 ± 5.93 ml kg·min ^-1 , 40.49 ± 6.63 ml kg·min ^-1 and 44.97 ± 7.00 ml kg·min ^-1 respectively for AT, RCP and maximal. Differences of HR at AT ( p < 0.001) and RCP ( p < 0.001) was observed. The HR before infection was 145.08 ± 10.82 bpm for AT and 168.78 ± 9.01 bpm for RCP and HR after infection was 141.12 ± 9.99 bpm for AT and 165.14 ± 9.74 bpm for RCP. Time-adjusted measures showed significance for body fat (r = 0.46, p < 0.001), fat mass (r = 0.33, p = 0.020), cycling power at the AT (r = -0.29, p = 0.045), and HR at RCP (r = -0.30, p = 0.036). Conclusion: A mild COVID-19 infection resulted in a decrease in EA's CPET performance. The most significant changes were observed for VO ₂ and HR. Medical Professionals and Training Specialists should be aware of the consequences of a mild COVID-19 infection in order to recommend optimal therapeutic methods and properly adjust the intensity of training.
Competing Interests: Authors DS and AM are a board members of the company Polish Society of Lifestyle Medicine. DS and AM do not receive any salary from the Polish Society of Lifestyle Medicine. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2022 Śliż, Wiecha, Ulaszewska, Gąsior, Lewandowski, Kasiak and Mamcarz.)